The present invention relates to a semiconductor device and a manufacturing technique thereof, and particularly to a semiconductor device wherein at least one semiconductor chip is mounted over a wiring board, and a technique effective if applied to a manufacturing technique thereof.
A semiconductor chip is mounted over a wiring board, electrodes of the semiconductor chip and connecting terminals of the wiring board are electrically connected to one another by bonding wires respectively, the semiconductor chip and the bonding wires are sealed with a resin, and solder balls are respectively connected to the back surface of the wiring board, whereby a semiconductor device of a semiconductor package form is manufactured. Such a semiconductor device of a CSP (Chip Size Package) form, which is a small-sized semiconductor package of the order of being slightly larger than a chip size or the semiconductor chip.
Japanese Unexamined Patent Publication No. 2003-92374 (Patent Document 1) has described a technique wherein in a semiconductor device having a wiring board including a main surface, an insulating film formed over the main surface and electrodes exposed from the insulating film and formed over the main surface; a semiconductor chip fixed onto the insulating film provided over the main surface of the wiring board via an adhesive interposed therebetween; conductive wires which respectively connect the electrodes formed over the main surface of the wiring board and electrodes of the semiconductor chip; and an encapsulator or sealing body which covers the semiconductor chip, the main surface of the wiring board and the electrodes, trenches are formed between the semiconductor chip and the electrodes by removing the insulating film over the whole region of its depth, and an outflowing portion of the adhesive (insulative resin) is allowed so as not to stay within each trench, flow beyond each trench and reach the electrodes.